Bending presses are known which use a light barrier arrangement to monitor a protected zone. For some processing procedures it is necessary to deactivate one or more light barriers in order to directly permit specific interventions in the protected zone. This takes place in accordance with the prior art, for example, by an emergency stop of the apparatus which is triggered by the intervention which ultimately has to be permitted and by a subsequent, repeated start pulse of the operator to continue the processing procedure, with defined light barriers then being deactivated during this continuation of the processing procedure. However, this has the disadvantage that the processing procedure is interrupted.
It is alternatively known to provide an additional switch to switch off the light barriers which is actuated prior to the start of the bending procedure, which results in specific light barriers being deactivated for a single, subsequent bending procedure. Such a bending press is known, for example, from DE 197 17 299 A1. However, this has the disadvantage that an additional switch to be actuated has to be provided at the bending press and has to be actuated by the operator.